Abstract: The triangle flexible hinge as a rotational element can be used to construct flexible module or compliant mechanism with better performance, such as wheel shape hinge and butterfly hinge. Building an accurate force-bearing model and analyzing its load-displacement characteristic is the key to designing a complicated hinge or mechanism. Based on an approximate cantilever model, an accurate rotation angle model of triangle flexible hinge under simultaneous actions of bending moment, tangential force and axial force is built. The calculation formula for axis drift without approximation is obtained, and a practical axis drift model is derived. The rotation angle and axis drift models all concisely represent the load-displacement relationship. The accuracy of built models is verified through finite element analysis.

Key words: Axis drift, Model, Rotation accuracy, Triangle flexible hinge